The present invention relates to a plate separator or destacking system used to remove an article (e.g., a culture plate or dish) from a stack of such articles; or, more particularly, to separate a first article (or culture plate or dish) in the stack of said articles from at least one second article stacked on top of the first article.
Biological samples such as body fluids (e.g., blood, urine, etc.) water samples, food samples, soil samples, etc. are frequently tested for the presence or absence of microorganisms (e.g., bacteria, fungi, etc.). Such tests typically require the samples to be combined with nutrient media to cultivate the growth of a sufficient amount of microorganisms in the sample to allow for reliable detection. Testing samples for evidence of microbial growth has historically been a manual process. Lab technicians will prepare culture plates, inoculate them with sample, place the inoculated plates in an incubator and periodically check the plates for the growth of colonies of bacteria. When there is evidence of microbial growth, a portion of the colony is picked. The picked sample is then combined with solution for downstream testing to determine the type of microorganism and what susceptibilities and resistances the microorganisms might have regarding antibiotics.
Because the manual laboratory testing is labor-intensive, efforts are underway to automate some or all of these laboratory processes. Automated processing is configured to prepare and monitor many plates in assembly line fashion. Platforms for automated culture plate processing provide an inventory of non-inoculated plates with growth media that are selected for processing. The platform, in response to an entered order takes a culture plate from inventory, inoculates the plate with the sample corresponding to the order, incubates the plate and periodically inspects the plate for evidence of microbial growth. All of these steps can be accomplished using automated handling of the plates, the sample and the reagents used to prepare and process the plate. These automated sample processing platforms are referred to as total lab automation.
Such automated medical testing systems typically stack the inventory of culture plates (containers such as petri dishes) for efficiency of storage and ease of access and automated processing. Although stored in stacks, each plate is processed individually. Consequently, the automated system must be able to remove individual plates from the stack so as to convey each plate to a designated testing location remote from the stack. In such systems, since each plate must be identified and tracked, the plates are often processed in the order they are provided to the system (“first in first out” or FIFO). In terms of automated processing of stacked articles, this means that the articles are added to the top of the stack and removed from the bottom, or vice-versa.
Removing a plate from the stack can destabilize the stack, damage the plate, cause the lid to separate from the plate, etc. Removing more than one plate at time can cause the plates to be processed out of order. This could result in the plate being inoculated with a sample intended for a different plate, wasting sample, processing time and the plate itself. Such errors can therefore compromise the integrity of the plate processing, cause cross-contamination, etc. Similarly, such problems can arise in other contexts where stacked articles are removed from the stack one by one for further processing.
Automated apparatus used to store and retrieve plates are known. Such devices receive and store plates in a stack, with automated mechanisms to add plates to and remove plates from the stack. One such device is the SorterA module that is part of the InoqulA automated apparatus for sample preparation that is sold commercially by Becton Dickinson.
Accordingly, apparatus for removing an article from a stack of articles without disturbing the stability of the remaining articles in the stack are sought.